IPL= Intense Pulsed Light, is not a Laser! IPL can deliver good results but Laser is better.
Laser hair removal is "supposed" to be permanent but...there are some factors involved such as Density of hair on your face, the color and thickness (darker and thicker is better), Fitzgerald Skin Type (lighter better), type Laser used/wavelength, number of treatments, and QUALITY of skin preparation for treatment (tight shave, skin exfoliated).
If you have light (blond, red, white or grey) hairs, consider Electrolysis instead, Laser will not remove those hairs, because they reflect the Laser energy, darker hair absorbs.
Face and neck first priority, it will take 4 - 8 treatments, approx. 8 weeks apart. Cost, you mentioned you are in Ireland, so its a little different than the USA, especially TEXAS, where due to a recent change in State Laws regulating LHR (Laser Hair Removal), the market is glutted and some places have shut their doors! In my case, I go to a large Medical School Dermatology Clinic for the LHR, has the latest gear, a very experienced RN that also has final say on the price, and can adjust accordingly.
From previous posts on Hair Removal, many say if you are getting Electrolysis, do it before starting HRT if possible, makes it easier to zap the hairs. As to side effects from HRT, no know contraindications or interactions known off. The only remote problem might be Melasma, but if you are not on HRT its not a problem anyway.
Bottom Line...shop around, a good LHR clinic or Salon will quote a price and might even have a Guarantee or Warranty. Look for a STABLE technician, one who will be there all the time (makes a big difference), avoid "package deals", better to "pay as you go".
Hope this helps.